﻿/*
 * Copyright (c) 2015-2016 Constantijn Evenhuis (blueprints@const.nl)
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
using Blueprints.Resolution;
using System;

namespace Blueprints.Defaults
{
    /// <summary>
    /// Describes an enumeration.
    /// </summary>
    internal sealed class EnumValueDescriptor : IValueDescriptor
    {
        /// <summary>
        /// Creates a new EnumValueDescriptor.
        /// </summary>
        /// <param name="type">The enum type.</param>
        public EnumValueDescriptor(Type type)
        {
            Type = type;
        }

        /// <summary>
        /// Gets the type this descriptor describes.
        /// </summary>
        public Type Type
        {
            get;
            private set;
        }

        /// <summary>
        /// Indicates whether <paramref name="value"/> can be converted to the correct type.
        /// </summary>
        /// <param name="value">The string representation of the object instance to create.</param>
        /// <returns>True if the value can be converted, false otherwise.</returns>
        public bool CanConvertFromString(string value)
        {
            try
            {
                Enum.Parse(Type, value, true);
                return true;
            }
            catch
            {
                return false;
            }            
        }

        /// <summary>
        /// Converts <paramref name="value"/> from its string representation.
        /// </summary>
        /// <param name="value">The string representation of the object instance to create.</param>
        /// <returns>The created object instance.</returns>
        public object ConvertFromString(string value)
        {
            return Enum.Parse(Type, value, true);
        }

        /// <summary>
        /// Converts <paramref name="instance"/> to its string representation.
        /// </summary>
        /// <param name="instance">The instance to convert.</param>
        /// <returns>The string representation of <paramref name="instance"/>.</returns>
        public string ConvertToString(object instance)
        {
            if (instance == null)
            {
                throw new ArgumentNullException("instance");
            }

            if (instance.GetType() == Type)
            {
                return instance.ToString();
            }

            return Enum.Parse(Type, instance.ToString(), true).ToString();
        }
    }
}
